Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper for easy removal of the biscotti after baking.
In a mixing bowl, combine the almond flour, granulated erythritol, baking powder, and sea salt. Whisk them together until they are well combined, ensuring there are no lumps.
Fold in your choice of chopped pistachios and pecans. Mix until the nuts are evenly distributed throughout the dry ingredients.
In a separate bowl, beat the egg and then add the almond extract. Pour this mixture into the dry ingredients, stirring until everything is combined into a dough.
Transfer the dough onto the prepared baking sheet. Shape it into a log that is about 2 inches wide and ½ inch thick. Smooth out the top and sides for an even bake.
Place the baking sheet in the preheated oven and bake for about 25-30 minutes, or until the log is firm and lightly golden.
Remove the baking sheet from the oven and let the log cool for about 10 minutes. Using a sharp knife, slice the log into 1-inch thick pieces.
Lay the slices cut-side down on the baking sheet and return them to the oven. Bake for an additional 10-15 minutes, or until the biscotti are golden brown and crisp.
Once baked, remove the biscotti from the oven and allow them to cool on a wire rack. This step is crucial for achieving the perfect crunch!